This review presents information on 1971 petroleum developments in 27 countries and areas. Ten countries had petroleum production; this totaled 1,689,090,000 bbl (4,627,648 b/d), a decrease of 2.8% from the previous year. The volume decline came mainly in Venezuela, the major producer of the region (76.7% of the total), where production was down 4.3% to 3,549,000 b/d. Production increased moderately in Argentina, Chile, and Brazil, and Bolivia's temporarily disrupted operations made a strong recovery; but downward trends in Peru and Trinidad continued, and Colombia's production was off slightly from a record 1970 level.

Total drilling decreased to 1,887 wells, 91 less than in 1970; but the number of exploration wells was 410, up by 20. Exploration drilling was carried out in 18 countries, but no new countries came into commercial production. Party-months of geologic and geophysical field work were: surface geology, 212 (329 in 1970); seismograph, 671 (659); gravity, 53 (51); and magnetometer, 5.0 (12.6).

Successful exploration drilling continued in eastern Ecuador and in eastern offshore Trinidad; heavy development drilling was done in several of the discovery areas; and first export production from the new major fields will come in 1972. The high level of 1970 exploration drilling effort on the Brazil continental shelf was maintained through 1971. Additional offshore drilling in Argentina and off the east coast of Nicaragua was disappointing; and results of first tests in the northern offshore Trinidad permits, and on the outer shelf of Guyana and of Surinam, have been only moderately encouraging.

The major acreage development of 1971 was the signing of the first service contracts in Peru, followed by several more in early 1972. A further highlight was formal award of the south-central Lake Maracaibo contract areas. Private companies did not acquire significant amounts of new exploration acreage elsewhere in South America during the year.